SEOUL, Feb. 11 (Yonhap) -- The South Korean military is pushing to develop unmanned attack helicopters capable of hitting North Korea's front-line bases as a way to counter growing threats from the communist country, a senior military official said Monday.

Seoul has been mulling ways to beef up deterrence and combat capability to cope with rising tension following Pyongyang's warning of a third nuclear test in response to the U.N. sanctions for its December rocket launch. Last week, South Korea's military chief warned of a pre-emptive strike even at the risk of war if Pyongyang showed intent to go through with a nuclear attack.

"The military is considering using unmanned combat helicopters to destroy North Korea's military bases used for infiltration, including artillery bases and a naval base for air-cushioned vessels," the military source said, asking for anonymity due to sensitivity of the issue.

Currently, technical reviews are under way on whether to develop a helicopter bomber or modify aged 500 MD helicopters to equip them with an unmanned aviation system, GPS and radar for early deployment, the defense ministry said in a press release, without elaborating on further details.

"Modification to an unmanned system could reduce pilot's weight and unnecessary equipment, which would speed up the flight," the source said. "It could be used as an unmanned combat helicopter, which could pose a serious threat (to North Korea)."

A fleet of 120 U.S.-made helicopters, introduced in the 1980s, have been used for reconnaissance and to carry wire-guided anti-tank missiles. South Korea has developed the indigenous Surion light utility helicopter to gradually replace the aged choppers.